Airplane



R. F. HALL O'ct. Z7, 1925' 1,559,090

AIRPLANE Filed Nov. 3, 1923 l 2 Sheets-Sheet 1.

wuentoz Oct. 1.27, 1925- 1,559,090

R. F. HALL l AIRPLANE A Filed Nov. 3, 1923 2 Sheets-Sheet 2 ja- Jjija. Ejea-11.4

72 J5 i fij" 76? Patented oct. 21, 1925.

UNITED STA l taANnoLrH E1s-PATENT OFFICE r. HALL, or ITHAGA, NEW Yoan, AssIGNoR lor'oNE-'rHmn ro 'rHnononn 1f. HALL, or WALLINeroHn, GONNECTICULAND or' ONE-SIXTH 'ro PAUL WILsoN,r or ITHACA, NEW YORK.

' AIRPLANE.

:Application filed November To all 'whom t may concern.:

.Be it known that I, RANDOLPH F.' HALL, a citizen of the United States of America, and a resident of Ithaca, county of Tompkins, State of New York, haveinvented certain new and useful Improvementsin Airs planes, of Whlch the following 1s a specifica- -typeof -a1rplane is generally adapted and intended for operation and use in'a cer#1 taincla'ss of service and for performing certain operations','and is so designed as to v de eaelol') a performance capable of fulfilling the operatingrequirements and meeting the operating conditions encountered inthe class lof service for which the type is designed' 'and intended. The performance of 'an air- "plane is dependentfuponcertain basic and fundamental factors: of which th'e9type and resulting alerodynamic characteristics vof the supportmngf'surface `or w1n'g employed 1s a '-"c'ontrolhn "one, particularly with reference tothe 1i ting capacity, climb, and s eed range, ineludinv the landingsspeed, o., the airplane.v f In l lane,i to' develop a certain desired pervrmnceiatype and design 0f 'supporting surface vor win-gi is employed having-v the requisite -a'erofoil section and curve, area,

and 'shape,.'.which with thel other control-ling factors-wil1'- result jin the v desired perf k ticsl ofthe sup ortg surface or wing with formance 'for` the'type vditions,`is not generally adapted or capable of operation with any degree ofeiciency o1 safety for other classes of service under condltions' requiring a performance other @lie-@design of a type'of air#y a, 1923. serial No'. 672,548.' y

thanl 4that for which designed, without changing or varying the factorsupon which the designed performance is based'and dependent; `suchfor example, as substituting a supporting surface or wmgs of a different type having the' requisite aerodynamical characteristics which together with the other` factors will develop the desired` performance. In the operation and use of airplanes 1t 1s frequently necessary or deslrable to perform a certain class of 'servlce or certain operations 'calling for a performance ofwhich the availabletypes are not capable;

as for example to decrease the landing speed,

yor to increase the lifting capacity of a type,

Where the available'types could be rendered "capable of. ythe required performance by substituting a .supporting surface o'r wings of different aerodynamical characteristics to meet the requirements ofL the desired'perf` formance. `However, to change the supporting surface for wings., of an airplane .and substitute wings 'of 'the'desired characteristics therefor, .is an operation requiring considerable time and expense, and results in a permanent change in the performance of the airplane, fromqthe performance for which designed Vand intended. `Therefor, this manner of changing-or modifyingthe performance ofal atype tov meet thel more or less emergency or temporary requirements for such changes encounteredin service, is

not generally practical or, feasible.

In attempts .to fulfill-the need for varying or changing the normal performance of an airplane to increase the range of possible servlces and operations of which 1t 1s capable, and to .thereby -meet the demands beyond oroutside of the normal performance, which the type may encounter in operation and use, various types and designs of supporting surfaces or Wingsl have beenl de. vised in which the performance controlling factors, such' asjtheincidence, camber, and

area, arev'ariableto :change the characteris- 'conditions "and requirements. However,` the provision of'a support-lng surface or wing having variable characteristics necessitates a more or less complicated Wing constructlon `and the provision of mechanism for4 operat-l Yoperating mechanism therefor.

ing the variable elements of the wing to change the characteristics thereof, with the resulting increase in the possibility of wing failure through breakage therein or in ,the Further, wings of the variable characteristic type are not adapted to incorporation lin or mounting on, or for substitution in place of, supporting surfaces or wings of conventional types on an airplane, Without removing such wings from the airplane, or completely and permanently redesigning and reconstructing the same and eliminating any possibility of readily and practically reconverting the wings to the original type and design from which changed.

Therefore, one of the main objects of the present invention is to providcfor readily changing the performance of an airplane in order to adapt the same to meet and fulfill the operating reqnirenients of services and operations beyond or outside of the performance for which originally designed and capable. by temporarily, or if desired permanently, varying or modifying the charac.- teristics of the conventional types of supporting surfaces or Wings of an airplane to develop the required performance without destroying or redesigning the original construction and design of the Wingsand in such a manner that the Wings as varied or modified can be readily reconverted or changed back to the original design and characteristics.

A further object of the invention is to provide a unit structure adapted to be mounted on or incorporatedY lwith an airplane supporting surface or Wing of conventional or other 4type and design, to vary or modify the controlling characteristics of the wing, such as the incidence, camber, or

area, and thereby change or vary the resulti ing performance of the wing.

A further object of the invention is to providea unit structure adapted to be detachably mounted on an airplane support.- ing surface or wing to vary or modify the controlling characteristics thereof and change the normal performance of the wing, without/,1, reconstructing or destroying the original twing construction or design, andA which uiiit structure can be readily detached to recovert the wing modified thereby to its original design and performance.

'A further object. of the invention is to provide a series of unit structures or panels having different characteristics and adapted tobe readily mounted on and detached from the supporting surface or Wings of an airplane to modify the performance controlling characteristics thereof and change the performance of the airplane, so that the performance of an airplane in service can be readily and practically changed to'meet the varying-demands of service by attaching the unit structures or panels to the wings haring the necessary characteristics to develop therewith the required performance.

A further object. of the invention is to provide for temporarilyor permanently changing'or modifying the aerofoil Section of a supporting surface or wing of conventional or other type, without reconstructing or dcstroyingtlic original construction and design thereof, so tliata wing so'modified can bc lreadily rcconvcrted to the original design and section, if desired.

A further obje-ct, of the invention is to provide as an accessory for airplanes, unitl structures or panels adapted for detachable mounting on the supporting "surface or wings of an airplane to modify the wing characteristics and change the performance of the airplane and thus increase the service and operation range of which the airplane is capable.

A further object of the invention is to provide-'means for modifying the characteristics of airplane supporting surfaces or wings` which is adapted to use with the conventional types and designs now in use, as well as with special designs constructed particularly foil use with ,modifying means of the invention. Y

A further object of the invention is to increase the practical use of highly specialistics of the type to develop the required performance for practical service and operatlons, in sucha manner that a modified wing can be readily. reconverted to the original design and characteristics and permit operation of the type for the service for which designed.

A further obj-ect of the invention is to develop a system of field or operating service for airplanes .by means of which the wing characteristics of -an airplane can be' readily and quickly temporarily modified in an eflicient and safe manner. to develp a performance beyond or outside of that. for which designed` to meet the emergency demands encountered in operation for a perl formance of which available types are not capable. Y

With the foreging and various other objects and results in view, which other objects, and results Willbe reailily recognized by those familiar with the aeronautical art from the followingmitplanation.l the invention consists incertain novel features in design and in the construction and combination of elements. as will be more fully and' particularly referred to and =pointed out hereinafter.

Referring to the accompanying drawings: Fig. l is a diagrammatical view in vertical transverse section through a conventional ioo wing with upper and lower panels embodying the invention in applied position thereon to modify the characteristics of the wing.

Fig. 2, is a diagrammatical view in verti -al transverse section through a wing with a characteristic modifying unit of panel applied to the lower or under-surface ofthe wing.

Fig. 3, is a diagraininatical view in transverse vertical section througl'i a wing .with a characteristic modifying unit or panel applied and mounted on the uppersurface of the wing, a similar panel of' a design such as not to change the area of the wing being `indicated by dotted lines. Fig. 4, is a diagrainmatical view in transverse vertical section through a wing with a characteristic modifying super-structure embody ing the invention built upon and applied to the upper and lower surfaces of the wing.

Fig. 5, is a vertical transverse section, more or less diagrainmatical, through a wing of the metal type with a u nit structure mounted on and applied to thel Aupper surface thereof to modify the characteristics of vthe wing.

'Fig 6, is a diagramma-tical view in vertical longitudinal section through a portlon of a wing having a superstructure applied to the upper and lower surfaces of the wing to modify the characteristics thereof.

Fig. 7, is a 'detail view, more or less diagrammatical, in front elevation of a portion of the leading edge hinge connection of the panels shown in Fig. 1.

-Fig'. 8, is a detaildiagrammatical view in side or end elevation of the hinge connec- .tion of Fig. 7 the leading edge portions of the panels being shown.

Fig. 9, is a detail diagrammatical View in side or end elevation of a trailing edge connection formed in one-piece and particularly adapted for use with the panels of the type of Fig. l.

Fig. 10, is a detail diagrammatical view in side or end elevation of another fornrof leading edge connection for use with upper and lower panels of the type of Fig. y1.

Fig. 11, 1s a detail diagrammatical view in end or side elevation of a form of trailing edge connection similar to the leading cation of the invention to an airplane. withoutintereriug with 4the normal rig-ging` rangenient thereof.

According to the broad principles of the invention as cxemplitied by the .illustrated embodiments,

-thepertormance of an airplane is changedV or varied by modifying the characteristics of the supporting surface or wings thereof', which maybe of eonventionalaor other design ortype`, without reconsticting or changing the design and mounting of the 'original supporting surface 'or wings,

and further in such a manner that thesupporting surface or wings as modified can be readily and quickly reconvertcd to the original characteristics and resulting performance from the airplane for which designed, .This is accomplished by utilizing the supporting surface or wing to be modified as a baseu'pon and from which a structure is detachably and removably mounted and supported to change those fac-v tors. such as the incidence, camber or area, upon which the aerodyiiamical characteristics and performance' of the wing are dependent, and result in a modified supporting surface or wing to develop the desired performance.

One possible form and embodiment of the means for carrying out the invention is .105

illustrated diagrammatically in Fig. l ofthe 7drawings as detachahly applied to and mounted on a supporting surface or wing 10 of conventional or any other desi red design and constriuftion. aerodynamical expression of the invention a unit structure or panel v1.1 is applied on and extending over the upper surface of the wing 10.,.and 'a unit structure or panel l2 is applied on and extending overthe lower' or under surface of-Vthe wing 10. The upper and lower panels 11 and 12 are extended forwardly and rearwardly a distance bevond the leading and trailing edge portions of the wing 10 and are ioined or meet to' form the leading and trailing edges and l5, respectively, of the modified wing. The onteinsurfaces lllarhl 12a of. the upper and lower unit structures or panels 11 and 12, respectively are curved or cambered chordwise of the wing, and are. suitably inclined.

In this torni and.

curved, or otherwise shaped 'and formed,

longitudinally -`or ys'panwise of the wing, so asvv to develop the desired or requlred aerofoil sectiony and shape yand. for the modi- 3 the panels 11 and 12 mountedand supported.

fied wing formed by the base wing 1() and thereon.

The depth or thickness of the ,unit structures or panels 1.1 and l2, in connection with the depth or thickness ofthe original or base wing 10 to'he modified, will determine the depth (ii-.thickness of the modified vwing Section, which can be formed of the required thickness for the performance desired, by

utilizing panels'having the proper depth, as

will be readily apparent.

embodiment of the invention typifiedby the use of upper and lower unit structures' or panels, not only the depth or thickness .of the original or base wing 10 is modied,

' but another characteristic'determining factor, the area, is modified, and the extent of this modification or increase in area is def termined by the distance the panels are extended beyond the leading and trailing edges of the original or. base wing 10, las

' well as by the distance, if any` which the ""panels may be extended beyond the tip of modified wing is a thick section wingof greater areathan the original wing 10 but -with substantially the same relative camber and incidence factors. However, it is to be understood, as will be apparent to those familiar with the aeronautical art, that the unit structures or panels 11 and 12 can be formed with any desired cambers and designed to provide any desired incidence when applied in mounted position on a base or original wing and develop a modified wing of the4 desired section and characteristics.

The wing modification units or panels 11. and 12in the example of Fig. 1, are detach? ably and removably mounted and supported in positionlon an modifying the original wing 10, which forms a base therefor. Any suitable or desired means or mechanism and construction and arrangement thereof, may be utilized for detachably mounting the panels 11 and 12 on the wing 10, and in the presentexample removable bolts or tie rods 16 are disclosed extended through and traversing the upper and lower panels 11 and 12 and the original wing 10, to detachably secure the panels in mounted position on the wing 10. The bolts ortie rods 16 can be provided with the retaining nuts 16a which are arranged to lie in countersunk bores or openings provided through the outer surface of the modification panels to In the present' prevent interruption of such surfaces by th [panels 11- and 12 are preferably connected or coupled together at their Vmeeting or joined ends which form the leading and trailing edges of the modified wing in mounted and applied osition of the panels on the baseor original)\vi1ig 10. vOne inanf ner of connecting and joining the meeting ends of-the panels in mounted applied position' is more or less diagralnmatically disclose-d in Fig. 1, in connection with the" de tail disclosures of'Figs. 7 and 8. The meeting forward ends of the upper and lower panels 10 and 11, which form the leading edge 14 of the modified wing, are pivotally connected -and joined by a hinge connection 17 which comprises, referring to Figs.

7v and 8 of the drawings, the hinge leaf forming members 17 and 17b fixed to and over the forward edges of the upper and lower panels 11 and 12, respectively, and pivotally coupled and connected by the hinge pin, rod or wire 17c which 'extends through and is -received by the opposite hinge leaf members 17` and 17. With the forward or leading ends of the upper and lower panels. thus pivotally connected and joined by the hinge connection 17, to apply the panels 10 and 11 to a yving to be modil'ied theyare swung open on the hinge connection to separated position and slipped over the leading ed e onto the base or original wing 10 and t en swung toward each other into mounted position on and over the upper and lower surfaces thereof. The panels are then xed in mounted position by lthe removable bolts 16. or other securing means. If desired, any suitable trailing edge connection is detachably mountedon and connecting the extended rear or after meeting and lined ends-of the panels 11 and 12 which of the modified wing, such for example,

,as the connection 18 diagrammatically indicated in Fig. 1 ofthe drawings. The trailing edge connection 18 can be in any of a number of forms and removably v secured over the meeting ends of the panels, as by bolts, screws, rivets or other removable attaching means. In' order to remove the panels 11 and 12 and convert the modified The, type of trailing edge connection' disform the trailing edge 15v closed in Fig. 1, is more or less diagrammatically illustrated in detail in Fig. 9, ando comprises a one-piece substantiall V or U shaped member or strip which is tted over the meeting `rear edges of the" up er and lower panels 11 and 12 which form t @trailing edge 15 of the modified Wing.- The.

trailing edge connect-ion -can be detachably secured on andconnecting the panels'by any suitable'fastening means (not shown), `such as bolts, rivets, screws or the like.

In Figs. 10 and 11 of thedrawings, another type of leading and trailing edge connection is disclosed, and' comprises a twopiece connection formed by members 18 and l 18h secured or fixed along. .the leading. or trailing edges of the upper and lowerpanels 11 and A,12,

respectively, and having ,out-W' wardly bent and extended flanged' portions which are detachably secured and connected Y together with the panelsy in mounted poteniiig means 191.

sition on a'base wing, by means of the removablel bolts or the like 18. Fig-lOvshows this type of connection applied to the leading edge 14 of the panels, and Fig.- 11 discloses the same applied to the trailing edge j thereof.

la distancegfrom the trailing edge of the panel,lby bolts, rivets or other desired fas- In fixed position the connecting strip 19, thus forms an angular or V-shape recess to receive the trailing edge fof an original or base wing 1 0,as indicated in Fig. .13 of the drawings.

In Fig. 2 of the drawings an original or base Wing 1() is modified to change the aerokvdynamical characteristics and resulting performance therefrom, in accordance with the principles of the invention, by the application and mounting of a modifying structure or panel 11 tothe lower or under Aface or surface of the base wing 10. rlhisstructure v or panel 1.1 is formedof the required vthickness oi" depth and with the required caniber to .form with the thickness 4or depth` and witlithe required caniber orciiivature of the uppersiirface, ,of the base wing 10, a modified wing of the desired section, camber, incidence, land area 'to develop the performance required.- iVith the lower panel 11', the area of the original orV base wing the panel 11 aresiiitably4 shaped and curved to merge into and form unbrokenveontinua- 'tions ofthe upper camberedvsurface of the l base wing 10. Any suitable or desired securing means, such as liereinbefore .referred to, may b e utilized for removably mounting and applying the modifying structure or a-iiel'll in'position on the base wing 10, an in the illustrated Aexample portions of removable bolts 16 are shown-which extend through the nap panel 11 and are ada ted to `engage the base wing 10 and detacha ly-.seciire the'panel in position thereon. An original or base wing 10 is illustrated in Fig. 3 of the drawings as modified by peruunit structure or panel .12 applied o n and extending over the upperl surface of the 'wing 10 to forni therewiththemodified wing :having the desired characteristics to develop ithe performance desired'. In this example of ,thelinventiom the modifying ,structure or .panel .12 is formed to extend in mounted position .a distance forwardly and' rearwai'dly beyond the leading and trailing edges, vres ectively, of the base wing 10, to provide t e leadin .and trailin edges 14 and' 15 yof the modi ed wing, an the under surfaces of the leading andtrailing edge forming'portions 14 and 15 are so curved Vthe detachable mountingthereon of an up- 1 as to merge with and form the proper for- 10.is increased due tothe extension of the forward andi-ear endsk of the panel a distance beyond the. leading and trailing edges respectively, of the base wing to form the leading and trailing edges 14 and 15 of the modifiedV Wing. The extended portions ,ofl

ward and rear continuations, respectively, of the under surface of the base wing, to provide the required lower or under contour and cainber for the modified wing, as will be clear by reference to Fig. 3 of the drawings. With the form of modifying structure or panel 12 the area of the original or base Wing is increased in the modified wing resulting from the mounting of the panelv thereon, and the caniber and incidence can be 'modified to the desired degree by proper formation and shaping of the panel, as

explained herein'before. However,- where` desired or necessary to secure the required' modifiedperformance, the modifyin structures or panels of the invention, oft e type of 12 "or other types, can be formed for v application and mounting on a base wing 10 without increasing the areathereof. i An example of a panel so formed of the type of y 12 is diagraminatically disclosed by. d0t ted lines in Fig. 3, as ajpanell 12 whiclriii mounted position,l does, not extend beyond.

the leading andifra ,'ilingL edges of the basen;1 wing 10 but hasjtheforward and rear edges terminating 'and merging with the leading and trailing edges of the base Wing 10 to form therewith thev leading and trailing edges '14f..a iid"15, respectively, of the modified wing. fBy this design and vformation of the modifying structure or panel, a I

modiiied Wing is provided of the same area as the original or base Wing from `which formed. As in the caseof the modifying ist structures or panels previously described, any suitable 'or desired means, such as bolts, tie rods, rivets, or the like (not shown) can be employed for detachably mountlng and securing the panels l2 and 12on and to the original or base ywing 10. A

The embodiments' and aerodynammal 'I adaptations resenting the principles of the invention', iagrammaticallydisclosed in Figs. l to 3 of the drawings and described as unit structures or panels, may be formed and constructedin any suitable or desired manner, as of a shell-like or hollow form, or.

of a frame-work upon which a skin or Acovering is applied to form the surface of the' modified wing, and itis not intended or def.

sired to in any way limit the invention to any particular form or construction.

As illustrative of another possible adaptation. of the principles of theinvention, a

modified wing is purely diagrammatically-l illustrated in Fig. 4 of the accompanying drawings, as formed by' a super-structure built or applied on and over an voriginal or base wing 10 without reconstructing or destroying the original wing, which latter can.

- be reconverted to its original form and design by removing the modifying superstruc-v ture therefrom. In the present example this modifying superstructure comprises a seriesy of stringers or formers 20 extending long1 tudinally over the upper surface of the wing 10, and a similar series of Vlongitudinal stringers extendmg over the lower surface `camberin the modified wing.

of the'wing. The stringers 20fof the upper and lower surfaces of the wing l0 are spaced apart chordwise thereof from the leading to the trailing edges of the wing, and` the `stringers lor .formers- 2O of each series are of varying thickness or depth, respectively, to develop the desired depth or thickness and Any suitable covering 6r skin 21 is vfixed to and extending over and across the upper and lower series of' longitudinal lstringers or formers 20 and covering and enclosing the base or original wing 10. The upper and lower skin 21 thus forms theupper and lowersurfaces of thev modified wing, and-f arejoined or meet at the leading 'and trailing'edges, respectively of the modified wing. Thus, the base wing is modifiedbysuch superstructure to present a thicker section and if 'desired to' provide a different camber and incidence from the base'wing. The superstructure can be arranged and constructed toincrease the areav of the base wing, where desired,'or can be arranged as shown in Fig. 4, so as not to increase the area. With such superstructure a supporting surface or 'wingl can'l be modified without reconstructing or destroying the original or base wing, and when desired the -superstructure can be readily removed to reconvert the modified wing to its origin'al form and characteristlcs.

mafioso.

'i InFig. 6 of the drawings'a portion of a modified base for original win 10 is diagrammatically disclosed in which a modifying superstructure of thetype shown in Fig. 4 is employed. However, in the form of Fig. 6, transverse stringers or formers 20 are secured on and extending-chordwise of the upper and lower surfaces of the original or base wing 1 0, and are spaced apart longitudinally or spanwisethereof. A covering or skin 2l is appliedon and extendingover the upper and lower series of transverse stringers 20', repectively, to complete and formA theupper and lower surfaces of the modified .wing as hereinbefore explained.

. lThe application of the invention to a supvporting `surface or wing of the metal type is more or less diagrammatically illustratedin Figs, 5 and 12 .of the drawings, in which example the original or base wing 10 is specially and particularly constructed and arranged for use with and modification by means embodying the invention, although it is to be understood that the invention is adapted and applicable to use with any type of metal wing ofthe conventional or other forms andl designs. 4The metal base or original wing 10', in the present instance is formed from a series of longitudinal, spaced U-section channelI beams 30 having the base sides disposed at the upper side of the wing and the open sides -thereof at the lower side of the wing, An upper metal skin 3l,-

smooth or corrugated, is fixed over and extending across the upper closed or base sides of the beams 30, and a lower metal skin 32 is fixed over and extending across the lower"- open sides of the beams 30, which latter terminate in fianged portions to which` the skin 32 is fixed in any suitable manner. The forward and rear end edges of the upper and lower skin or coverings 3l and 32 are joined and `secured 'together in the usual Vmanuel' to fornrthe leading and trailing' edges of the wing, as will be clear Vto those skilled in the art. If desired or found ex.

' pedient-,transverse 'metalstiffening ribs such or base wing 10, and includes the long-i1 tudinal U-section beams 30 which are disposed with their closed or basev sides at the under or lower sides at' the lower side of the unit structure and their open sides terminating in-'lianged portions over and to which a covering or skin 35 is fixed, in

a manner similar to the skin 32 of the original wing 1-0. I n order to strengthen and stiden the unit 34, transverse ribs are fixed in and extending between the `longitudinal beams 30, as hereinbefore reerred to with reference to the similar r1b`s 33 in the originarl win 10. In the form of unit 34 disclosed lgierewith the under or lower side thereof is uncovered and the longitudinal beams 30 are spaced a distance apart equal to the spacing of the similar so that when the modifying unit is applied to and mounted onl the upper surface of wing 10', the closed' or base -sides of the beams 30 ofunit 34 will rest upon the upper skin 31 directly above and alined with the beams spectively of the wing 10. The metal original or b se wing 10 is modified by applying the u it metal structure 34 on the upper side thereof with the beams 30 of the wing alined with the-beams 30v of the unit, and the" skin 35 of the unit.

extending over the beams 30 thereof and suitably detachably connected at the forward and rear edges thereof to the leading and trailing edges of the original wing, so as to form therewith the leading and trailing edges, respectively, of the modified wing.

The forward and rear edges of the skin 35- canI be detachably connected to the 'original wing, as by the leading odge hinge type of connection 17 having a removable hinge pin or rod, andthe use of removable bolts, vrivets or the like (not shown) for securing the trailing edge. The skin 35` is, of course', mounted and secured over the 'beams 30, which are of thel proper varying depths, to secure the desired camber and contour of upper surface in the modified wing. The unit structure 34 is d etachably secured in mounted positionon the original or base l Wing 1U by spaced series of bolts 36 extending through'the adjacent alined closedor base ends of the pairs of Wing beams and unit structure beams 30, respectively, these bolts 36 extending through the upper skin 31 of the base wing`10 and .firmly removably attaching the unit structure 34 in position modifying the base or original wing, as clearly shown in Fig. 5 of the accompanying drawings. lOpenings or hand v lhrough the upper' skin or covering 35 o f tliemodifying unit 34, directly above the detachable se-` curing bolts 36, respectively, so thatsaid bolts are ,accessible for attaching'and detaching the sameto permit of securing and removing the modifying unit on and jfrom the original or base wing 1U. Similar openings or hand holes 37, can be formed through the lower skin 32l of wing 10 for access therethrough tov the lower end of the securing bolts 36, or other attaching means, if found desirable or expedient.

can be .suitably covered or closed to prevent air interference in flight, by removable fabric or the like patches (not shown) varnislied or otherwise secured over and covering the openings, or by removable closure plates,. (not shown), as will'be readily understood.

Attention is directed to the fact that in the adaptation of the invention disclosed in Fig. 5, the main elements, original wing and modifying unit, can be in effect reversed, by securing the upper skin 31 to the lower side of unit 34 to forni a complete wing thereof, and leaving the upper side of win 10 uncovered so as to form a unit modifying structure applicable for mounting on the lower-or underside lof a Wing of the general type illustrated.' Further, the modifying structure or panel, such for example :as the upper unit 34 of Fig. '5,-

can .be designed and formed to provide a wing by applying a lower skin therfeon havwhen ap lied to a wing such as 10 to modify t e saine, the lower skin of the unit is superposedupon the upper'skin 31 ofthe original wing, thus inefl'ect providing a wing formed of sections each of which provides a complete wing, the sections being separable orj detachable to" permit use of one thereof as a' wing.

As an illustration and example ofthe application and use ofthe rinciples of the invention, an fairplane A o more or less conventional design embodyin la biplane truss is disclosed diagrammatica ly in Fig. 14`of the drawings, as liavingthe su porting surface or wings thereof modified 1n accordance with the invention. The airplane shown embodies a biplane truss comprising the upper and lower wings 10 and a bracing or.

rigging arrangement therefor formed bythe struts or the like S, in the'usual oran'y suitable manner familiar to those skilled 1in this art. The` airplane A with the biplane wing truss will develop a. certain performance which is dependent upon certain controlling factors, of which the characteristics of .the K upper vand lower wings 10. form a major factor. The designed performance of the airplane A can, therefore, be changed by `modifying or varying the characteristics of the wings to meet/the requirements of the desired performance. In accordance with the invention the wings v10 of .the airplane A are modifiedby4 the application andvdetaclii and rigging arrangement S thereof. Y Y In the ist example illustrated the upper Wings 10 Vare provided with the unit structures or modifying panels 11 applied and detachably mountedv on the upper sides thereof, and the lower wing 10 1s provided with the unit -readily applied and mounted on the wings 11) without removing or reconstructing the same, or without rearranging or removing the riggingS thereof. When it is desired to reconvert the modified wings to' their original design `and characteristics. lthe modifying structure 11 and'12 is removed and the airplane returned to its original performance. The application and removal of the modifying structure or panels to and from the Wings of an airplane can be readily performed onA the field Without requiring the services of other than available field personnel or the us'e ofspecial equipment.

With lthe invention it is' possible to readily change the performance of an airplane,

without withdrawing the same from service, to meet the requirements of aiservice beyond or outsidev of the performance range for which designed, by applying a modifying structure in accordance with 'the invention to the supporting surface ofthe airplane to foriii'therewith aanodiied' supporting sur-- face having .the necessary, characteristics.' After completion of the service --for which modified, the modifying structure canv 'be readily removed from the supporting surface of the airplane and reduce or recouvert the same to the original design and characteristics. The invention is of particular value for use with airplanes of the various types in service where it may bedesired to temporarily or permanently employ a type for certain operations for which the designed performance is not efficiently capable, as for example, Where it is desired to increase the lifting capacity or reduce the landing speed of a type to meet the requirements of a certain service. Further, bythe invention lit is possible to convert special types, such as racing or high speed airplanes, to practical and general utility bymodifying the supporting surfaces thereof to increase the lifting capacity and reducing the landing speed. Again, in cases ofunsatisfactory performance the application of modifying structure embodying the invention can be emplofyed ace ' to vary or change the supporting sur characteristics to` effect a possible remedy. The invention contemplates andl provides for thc formation of a series of modifying structures or panels having different characteristics for use With a type of slipporting surface and mount-ing thereof, each structure when applied to the supporting surface forming a modified surface having different characteristics. and resulting performance, so that a type may be operated over a Wide range of services by selecting and applying the modifying. structure which with the original supporting surface-Will develop the required characteristics. In this manner field service can be developed for lair lanes which will permit of-their being readi y and quickly .converted to develop the required performances to meet t-he exigencies of service requirements and operating conditions. rlhe modifying structures for a type can be furnished with each airplane by the manufacturer as accessories therefor, or a service can be maintained from, which operators can secure the vdesired modifying structures.

lVhile the-'accompanying drawings dia- 90 grammatically disclose embodiments of the invention applied tothe Wings of an airplane, it is to be understood as Will e readily rccognized by those skilled in t leva-eronautical art, that the invention and prin-v ciplesinvolved are equally. adapted to use on other performance controlling elements,

snchas the control surfaces of an airplane.

The modifying structure,v units or panels diag'rammatlcally presented herewith as ex- 100 `'tending completely over and covering aside or, sidesof a supporting surface are merely for purposes of explanationand not byway oflimitation,l andit is desired 'to call attention to the fact that the invention contemplates and includes any form of element or structure applied to a supporting or control 'Surface for .modifying the characteristics thereof, irrespective. of whether the struc- Y ture completely covers the surface in either a chordwise or a ispanivise direction.

Attention is directed to the fact that the modification structures orI unitsvar'e designed and intended where necessary to reinforce the strength of the original or .base Wing 11.5 upon which mounted, so that theresulting l modified wing Will-possess the requisite factor of safety tocarefor` additional loads which may be imposed thereon. v 1

The term structure or the term panel, wherever they appear in. thev appended claims .are employed in av broad,- generic s sense' to include any formand design' of construction or arrangement for application to a supporting or control surface toV modify the characteristics thereof. .Y

It is further evident that'V various 4 changes, modifications, variations and substitutions might be resorted to, and hence -itl is not desired or intended. to liinit the inyention to the exact disclosures hereof. Desiring to protect my invention in the broadest manner legally possible, what I4 claim is:

1. In combination Withvan aerofoil, a tenivporary rigid unit structure fixed over a surface thereof to modify the aerodynamical characteristics of=the aerofoil, the aerofoil forming`a support therefor, the said rigid and each of said structure@ modifying the supporting surface to develop a different performance, respectively, from the airplane.

4. In combination With an airplane Wing of the metal type embodying a series of Wing beams enclosed Within a skin, a unit modifying structure including a series. of'

beams having a skin extending thereover 'across one side thereof, the said unit structure mounted on one side of said wing with the beams thereof vertically alined with the wing beams and the skin thereof outermost to form a modified Wing, means detachably connecting said alined beams, and means de tachably securing the ends of the vskin of said unit to said Wing.

5. A panel constructed and arranged to be mounted on an aerofoil extending over a surface thereof and presenting an outer surface cooperating with the aerofoil surfaces to form a modified aerofoil therewith, the inner side of said panel open and arranged to fit over and be closed by an aerofoil on which mounted. l

6. A panel constructed and arranged tobe mounted on an aerofoil extending over a surface thereof and presenting an outer sur-4 face merging into the leading and trailing edges of the aerofoil and cooperating with the aerofoil surfaces to form a modified aerofoil, the inner side of said panel open and closed by the surface of an aerofoil on which mounted.

7. In combination, an airplane including a main performance-controlling supporting surface having aerodynamical characteris-V tics todevelop a predetermined performance for the airplane, a substantially rigid tem- Aporary structure mounted in fixedl position on said supporting surface and cooperating therewith to form a modified supporting surface capable of developing ay different performance for the airplane, andsaid temporary structure completely removable from the supporting surface and the airplane yto convert the main supporting surface to its original characteristic and performance.

8. In combination with an airplane including a performance determining main supporting surface having non-variable aerodynamical characteristics to develop a predetermined performance for the airplane, a temporary performance modifying accessory embodyinga substantially rigid structure mounted in fixed relation on and supported by said supporting surface lWithout major structural change in the latter, the` said structure arranged and constructed to form With the said supporting surface a modified supporting :surface having aerodynamical characteristics to develop a different performance for the airplane, and the said structure detachable and completely removable 'from the supporting surface and the airplane, the said supporting surface with said temporary structure removed convertl'ed .tov its original characteristics and vthe airplane to its original performance.

9.` In combination With an airplane including la performance determining main supporting surface having non-variable aerodynamical characteristics to develop a predetermined performance for the airplane, a temporary performance modifying accessory embodying a preformed unit structure mounted in fixed relation fitting onto and supported by said supporting surface without structural modication of the said supporting surface, the said unit structure arranged and constructed with the outer surface thereof cooperating with the supporting surface to form' a modified supporting surface for the airplane having different characteristics and a modified performance, and the said unit structure completely removable from the supporting surface and the airplane, the said supporting surface A converted to its 'original characteristics and structural unity with the unitstructurere-A moved vvithout reconstruction of the said supporting surface.

10. In combination with an airplane including a performance determining main supporting surface having non-variable aerodynamical characteristics to developa predetermined performance for the airplane, and exterior trussing from one side of said supporting surface; a temporary structure mounted in fixed relation on the side of said supporting surface opposite ysaid trussing 11. In combination `with an airplane including a supporting surface of the multiplane type formed of wings having nonvariable characteristics to develop a predetermined performance for the airplane, a t-emporarystructure mounted in fixed position on each wing without structural change in the wings, each of said temporary structures arranged and constructed to forin with the wing ony which mounted a modified wing having different characteristics and the modified wings forming a multiplane supporting surface developing a different performance for the airplane, and each of said temporary structures removable completely from the wing on which mounted to convert the wing to its original characteristics and change the multiplane supporting` surface ,formed of said wings to develop the original performance for the airplane. Y

12. In combination with an airplane of the biplane typegincludiii upper and lower wings of the non-varia le characteristic type to develop a predetermined performance for the airplane, and trussing extending between said wings; a temporary structure mounted in fixed position on the .upper surface of the upper wing, and a temporary structure mounted in fixed position on the lower surface of the lower wing, each of said temporary structures 'arranged and constructed to cooperate and form with the wing on which mounted a modified wing having different characteristics', and said temporary structures formed with respect to each other so that the resulting modified wings provide a biplane supporting surface capable of developing a different performance for the airplane, the said temporary structures completely removable from said wings and the airplane to 'convert the wings to their original characteristics without structural change therein.l

13. A. characteristic modifying structure for acrofoils,l embodying a pair of panels constructed and arranged to fit over the upper and lower surfaces, respectively, of an aerofoil and to form therewith an aerofoil of different characteristics in mounted position of the panels, and means for detachably securing said panels in mounted position on an aerofoil.

14. characteristic and performance modifying structure for, an aerofoil, einbodying a panel lconstructed and arranged v to fit over the upper surface of an aerofoil, a

panel constructed and arranged t'o fit over Ithe lower surface of theaerofoil, said'pancls o'f'greater chord than the chord of thc' aerofoil and in mounted position on the aero- `foil forming a modified aerofoil therewith,

and means for detachably connecting the forward and rear edge portions of said-panels in mounted position thereof to define the leading and trailing edges of the modified aerofoil. y X

15. As a newA article of manufacture, a performance modifying accessory for airplanes,embodying a complete substantially rigid unit structure specifically designed for use with an airplane wing of givenform and characteristics, the said completel unit structure constructed and arranged to fit on and besupported by the Wing without strucv tural modification in the wing and in mounted position fixed with respect to the wing in cooperative relation therewith forming. a .modified wing of different characteristics, the said unit structure completely removable from a wing without structural change in the latter, and meansv for detachably fixing said unit structure on a wing, the said means removable with said structure from a wing on which mounted.

16.-As anew `article'of manufacture, a performance modifying accessory for an'- planes, embodying a unit structure for application to a given airplane wing having vnon-variable aerodynamical characterlstics, the said unit structure consisting of a frameformed on one side to fit over and receive a surface of the giyen wing and coverel on the other side by a skin havin a eamber to cooperate-and form with the wing on which mounted a modified wing of dif: ferent characteristics, and means for removably fixing said'unit structure on the given wing, said structure completely l removable as a unit from the given wing on which mounted without structural change in the wing. l v

17. As a new article of manufacture, a performance modifying accessory for airplanes, embodying a unit structure specifically designed f'or use with an airplane supporting surface of given form and charact'eristics, said unit structure formed to be mounted in fixed position on the supporting surface .in cooperative relation therewith to form a modified supporting surface of different characteristics,l the said unit struc- ,ture completely detachable and removable from a supporting` surface to convert the surface to its origlnal form and characteristies, and means for removably fixing said unit structurein position on a supporting surface to modify the characteristics thereof. 18. As an accessory for airplanes, a series of performance modifying unit structuresthe said unit structures in mounted position each .forming with the supporting surface a modified surface of different characterismodified aerofoil'therewith, the said panel tics,- respectively, each unit structure comof greater chord than the aerofoil and 'havpletely removable from the supporting suring the forward and rear portions thereof lface on which mounted to convert said surextending beyond the aerofoil fol-med to 5' face to its original characteristics, Aand provide the leadin and trailing edges of l5 means for removably fizking anyl desired one the modified aerofoll. l of said unit structures tothe given sup- Signed at Ithaca, NewYork, this 29th day l porting surface. of October, 1923.

19. In combination vvith an aerofoil, a 10 panel detachably mounted thereon to form a RANDOLPH F. HALL. 

